Earlier quoted context omitted.
Because of the ongoing massive costs savings it is expected that within 2015 or so it will be cheaper for house owner's to produce their own energy with photovoltaic than buying it. (Without governmental support) This will be a massive game changer: Decentralized, DIY, prosumer energy connected in a smart grid. The private rooth area and climate in for example Austria is enough to produce 1/3 of the electric energy u…
Citation needed. Is this with photo-voltaic cells built with dangerous and scarce materials?
Hawaii: already competitive (2009), California: 2011 (assuming 3kW plants)
Reuters [2] writes that "very sunny countries could reach that breakeven in five years[2012] or so, and even cloudy Britain by 2020."
The breakeven is called Grid Parity http://en.wikipedia.org/wiki/Grid_parity
[1] http://www.wm.baden-wuerttemberg.de/fm7/1106/Endbericht%20Br... (German, 2009, this is the report cited by taz.de)
[2] http://www.reuters.com/article/2007/10/19/environment-solar-... (2007)